In many contexts, there is a need for a thin-walled container of plastic material, in which the container, at least in its thin-walled portion, consists of oriented material. The desire that the thin-walled material be oriented is conditioned by the fact that the material will thereby generally possess superior mechanical strength properties than the non-oriented material. Naturally, the property of being thin-walled affords the obvious advantage that the material quantity in the container is reduced, and thereby the material costs of the container. It is normally a wish in this art that the mouth portion of the container consists of thicker material, in particular in practical versions in which the container is intended to be emptied of its contents in portions. As a result of the thicker material, the mechanical properties of the mouth portion will be improved (the mouth portion becomes more stable), and handling of the container is generally facilitated in connection with its opening and/or its reseating. One example of a container in which the above-outlined objects exist is a tube for mustard, fish paste, caviar etc. A container designed as a tube and employed for the above-mentioned objects must also be easy to compress in order to facilitate the forcible discharge of the contents of the container.
Injection moulding of a container of the type disclosed in the preceding paragraph is extremely difficult, since the material fed to the mould cavity is forced to pass through a narrow gap-like aperture in order to be displaced to the parts of the mould located most distally from the injection nozzle. This places extreme demands on temperature control of the molten, injected plastic material, as well as on the properties of the plastic material itself, As a result, containers produced in accordance with the technique described in this paragraph will be of undesirably large wall thickness.